In Automatic Speech Recognition, continual learning or incremental learning has been explored in a number of monolingual scenarios. The hybrid HMM models were explored in continual learning by learning different datasets such as World Street Journal, Reverb, Librispeech and Chime4 consecutively [1]}. In a similar manner, the sequence-to-sequence model can also be trained on different English datasets with the goal of evaluating the performance in each domain after training on another [2]}. Recently, the replaying from memory approach has been applied to online continual learning [3]} without a clear boundary within task.
